The following names are correct:
a
image1
arg_5
s2p6d4
The following names are incorrect:
2arg (starting with number)
arg-27 (contains non-literal symbol)
param$ (contains non-literal symbol)
Numbers may start from sign, point or digit and may contain only digits.
The following numbers are correct:
.095
+2334
-.3235
-123.234
2343.454
The following numbers are incorrect:
-.32.34 (two points inside number)
4534a44 ('a' is not a digit)
344.-34 (sign inside argument)
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaCalculatorLib_SetFormula(formula_str))
{
//error handling
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaCalculatorLib_SetFormula(formula_str.GetBuffer(1000)))
{
//error handling
}
FormulaCalculatorLib_Calculate
The function calculates the formula.
BOOL FormulaCalculatorLib_Calculate(double* double_res,char* arg_list)
Parameters:double_res - [out] result of calculation.
arg_list - [out] argument list.
Return values:
If the function succeeds, the return value is TRUE. Otherwise, the return value is FALSE.
Remarks:
Use the function calculate the formula. If argument list is empty (arg_list[0] is 0) then the
formula calculated successfully and there are no undefined variables found. Otherwise argument list contains list
of undefined variables (arguments), separated by comma (',') and double_res is always 0.
Example
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaCalculatorLib_SetFormula(formula_str))
{
//error handling
}
double res;
char arg_list[1000];
if(!FormulaCalculatorLib_Calculate(&res,arg_list)
{
//error handling
}
if(arg_list[0])
{
//arg_list contains argument list, separated by comma. For this example - "a,b"
//define arguments using FormulaCalculatorLib_AddArgument, then call FormulaCalculatorLib_Calculate again
}
FormulaCalculatorLib_Reset
The function resets the calculator.
BOOL FormulaCalculatorLib_Reset()
Parameters:none
Return values:
If the function succeeds and formula is valid, the return value is TRUE.
Otherwise the return value is FALSE.
Remarks:
The functions resets statement and argument structures of calculator.
Example
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaCalculatorLib_SetFormula(formula_str))
{
//error handling
}
double res;
char arg_list[1000];
if(!FormulaCalculatorLib_Calculate(&res,arg_list)
{
//error handling
}
if(!FormulaCalculatorLib_Reset())
{
//error handling
}
FormulaCalculatorLib_AddStatement
The function adds calculation statement to the calculator.
BOOL FormulaCalculatorLib_AddStatement(char* arg1,char* arg2,char* oper,char* funct,char* res)
Parameters:arg1 - [in] left argument (operand) of statement or argument of function.
arg2 - [in] right argument (operand) of statement.
oper - [in] operation.
funct - [in] function.
res - [in] name of result.
Return values:
If the function succeeds, the return value is TRUE. If the function fails, the return value is FALSE.
Remarks:
Use the function to add calculation statement to the calculator.
Usually data received from FormulaParserLib_GetStatement must be used here.
Refer to the FormulaParserLib function reference
for the details on FormulaParserLib_GetStatement.
Example:
for(long i=0;i<statement_num;i++)
{
char arg1[1000],arg2[1000],oper[1000],funct[1000],res[1000];
if(!FormulaParserLib_GetStatement(i,arg1,arg2,aoper,funct,res))
{
//error handling
}
if(!FormulaCalculatorLib_AddStatement(arg1,arg2,aoper,funct,res))
{
//error handling
}
}
FormulaCalculatorLib_AddArgument
The function adds argument to the calculator.
BOOL FormulaCalculatorLib_AddArgument(char* name,char* val_str)
Parameters:name - [in] argument name.
val_str - [in] argument value.
Return values:
If the function succeeds, the return value is TRUE. If the function fails, the return value is FALSE.
Remarks:
Use the function to add argument to the calculator.
Used when undefined variables are present in formula expression.See example...
Example:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaCalculatorLib_SetFormula(formula_str))
{
//error handling
}
double res;
char arg_list[1000];
if(!FormulaCalculatorLib_Calculate(&res,arg_list))
{
//error handling
}
if(arg_list[0])
{
//now "a,b" is in arg_list
if(!FormulaCalculatorLib_AddArgument("a",10))
{
//error handling
}
if(!FormulaCalculatorLib_AddArgument("b",20))
{
//error handling
}
if(!FormulaCalculatorLib_Calculate(&res,arg_list))
{
//error handling
}
//arg list is empty. The result is calculated...
}
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